Questar Gas provides retail natural gas-distribution service to almost 900,000 customers in Utah, southwestern Wyoming and a small portion of southeastern Idaho. Questar Gas is regulated by the Public Service Commission of Utah and the Wyoming Public Service Commission. Historically, about half of the natural gas sold to Questar Gas retail customers comes from Questar-owned supplies that are typically more-stably priced than gas purchased from other suppliers. Questar Gas is also one of the most efficient natural gas utilities in the nation. As a result, rates paid by Questar Gas customers are traditionally among the lowest in the country. A Questar Gas predecessor began serving customers in 1929. In the decades since, there has never been a major natural gas service interruption.